MAXIM (Sir HIRAM STEVENS, 1840-1916, inventor and scientist, invented the Maxim gun, pioneer of manned flight) THE AUTOGRAPH MANUSCRIPT OF HIS GROUND-BREAKING ARTICLE ON FLIGHT, 'Aerial Navigation: The Power Required', in which he predicts a military rather than commercial use for aeroplanes, with autograph and editorial revisions and corrections, passages both deleted (particularly of Maxim's honorific titles) and added, and with casting off and other markings by the printer including stenographers' or compositors' names, and also with ink marks and light smudges and soiling from compositors' fingers when used to set up the article for publication in The Century magazine for May to October 1891, 39 pages, quarto (two inserted 'A' leaves somewhat shorter but text complere), written on lined paper on the rectos only, no date [but 1891]

Maxim, known as 'the Edison of England' though born in America, was the first inventor to fly a man off the ground by means of powered flight in an aeroplane, though it was only at a few feet and for about 200 yards.

In this article, which dates from the earliest efforts to achieve powered flight in modern times, Maxim describes a machine for ascertaining the amount of power required to achieve flight with a screw-driven aeroplane. In an added note he qualifies the use of the word navigation as perhaps not being the right term 'to use in connection with a machine for traveling in the air. The French I believe have agreed on the term "Aviation" in case they ever succeed in flying.'

After commenting on the French balloon called 'La France', Maxim makes some general remarks in relation to bird and insect flight and on earlier experiments:

'Every living creature, bird, or insect, which has been able to raise itself from the earth and to propel itself through the air has a body many hundred times heavier than the same volumeof air, and is endowed with the power of exerting great mechanical force in proportion to its weight. It is the expending of this physical force upon the surrounding air that enables it to fly. But the actual force required by birds in their flight has until recently been largely a matter of conjecture. Many unsatisfactory attempts have been made with dynamometers attached to the bird itself to measure the force of its muscles, but very little of value has been accomplished in this direction...'

He then discusses the question of power needed to propel the goose, albatross and turkey-buzzard in particular, the last two requiring less power because of their large wing-surface and the angle of their wings. From bird flight he leads to what is needed for powered flight:

'The wings of a bird flying perform a two-fold function. They form primarily an aeroplane which supports the body after the manner of a kite, and, secondarily, a propeller for driving the aeroplane forward. I think all scientists are agreed that if we are ever able to navigate the air it must be on the aeroplane system; that is, the weight of the machine and passenger or passengers must be carried by a large plane driven at a high velocity through the air. There is, however, some difference in opinion in regard to the proper manner of propelling these planes...I am in favor of a scew- propeller, because with it I find a high-degree of efficiency, and the possibility of applying a large amount of force in a continuous manner without any vibration or unsteadiness in action...'

He goes on to describe in detail the machine he has constructed 'to ascertain the amount of energy required for flying, and also to ascertain what influence, if any, the factor of size has upon flight...' and concludes 'From the foregoing it would appear that if a machine with a motor complete can be made to generate 1 horse-power for every 100 pounds, a machine might be made which would successfully navigate the air.'

He then states that 'After studying the question of motors for a good many years, and after having tried many experiments, I have come to the conclusion that the greatest amount of force with the minimum amount of weight can be obtained from a high-pressure compound steam-engine using steam at a pressure of from 200 to 350 pounds to the square inch.' This he follows with the announcement: 'lately I have constructed two such engines each weighing 300 pounds...It would appear therefore we are within measurable distance of a successful machine for navigating the air, and I believe it is certain to come within the next ten years whether I succeed or not.'

Maxim predicts that the use of such machines will be more military than commercial: 'It will at once become an engine of war, not only to reconnoiter the enemy's positions as has been attempted with the so-called dirigible balloons, but also for carrying and dropping into the enemy's lines and country bombs charged with high explosives. It does not require a prophet to foresee that the successful machines of this character would at once make it possible for a nation possessing them to paralyze completely an enemy by destroying in a few hours the important bridges, armories, arsenals, gas and water-works, railway stations, public buildings, etc., and that all the modern means of defense both by land and sea which have cost untold millions would at once be rendered worthless...' He concludes: 'Flying-machines of the future will of necessity be of a complicated and delicate nature, and will require the very highest order of scientific and mechanical skill to construct and operate them. France is to-day the only country in the world which has the plant and in which it would be possible to manufacture all the material and to construct a machine such as I am now experimenting with. Flying-machines will therefore be employed only by the rich and highly civilized nations. Small nations and half-civilized tribes will still have to content themselves with their present mode of welfare.'